package server;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * @author HZF
 * @date 2020/6/27 10:55
 * @description
 */
public class StaticResourceUtil {
    /**
     * 获取静态资源文件的绝对路径
     * @param path
     * @return
     */
    public static String getAbsolutePath(String path){
        String absolutePath = StaticResourceUtil.class.getResource("/").getPath();
        return absolutePath.replaceAll("\\\\","/") + path;
    }

    /**
     * 读取静态静态文件输入流，通过输出流输出
     * @param fileInputStream
     * @param outputStream
     */
    public static void outputStaticResource(FileInputStream fileInputStream, OutputStream outputStream) throws IOException {
        int count = 0;
        while(count == 0 ){
            count = fileInputStream.available();
        }
        int resourceSize = count;
        //输出http请求头
        outputStream.write(HttpProtocolUtil.getHttpHeader200(resourceSize).getBytes());
        //读取内容输出
        long written = 0;//已经读取的内容长度
        int byteSize = 1024; //计划每次缓冲的长度
        byte[] bytes = new byte[byteSize];
        while(written < resourceSize){
            if(written + byteSize > resourceSize){//说明剩余未读取大小不足一个1024长度，那就按真实长度处理
                byteSize = (int)(resourceSize - written);//剩余的文件内容长度

                bytes = new byte[byteSize];
            }
            fileInputStream.read(bytes);
            outputStream.write(bytes);

            outputStream.flush();
            written += byteSize;
        }
    }
}
